FIG. 1 illustrates a schematic diagram of an LED lighting system, such as an LED light bulb 100. Light bulb 100 includes a base 102, such as an Edison-type screw-in base, coupled to a housing 104. Within housing 104 is an open cavity 106 for receiving the electrical components of light bulb 100. Electrical leads 108 extend from base 102 and are electrically coupled to a substrate, such as a printed circuit board (PCB) 110. One or more electrical components 112 are mounted on PCB 110. Electrical components 112 may include circuitry for power conversion and drive mechanisms for light bulb 100. Such circuitry may include resistors, rectifying diodes, capacitors, and Zener diodes. For example, rectifying diodes are typically used for AC to DC power conversion. Capacitors, on the other hand, may be used as wave-rectifiers to reduce LED flicker.
Lamp 100 also generally includes one or more passive heat management components, such as an aluminum heat sink 114. As shown in FIG. 1, heat sink 114 completely surrounds housing 104. However, alternative systems include a heat sink disposed adjacent to housing 104, without necessarily surrounding the housing. In general, heat sink 114 supports and draws heat from one or more LED chips 116. One disadvantage of LED lighting systems with passive heat sinks is that heat management is limited by the thermal conductive properties of the heat sink material and form factor.
Lamp 100 may also include one or more photo down-conversion elements to convert monochromatic light emitted from LED chips 116 to polychromatic light. For example, phosphor coatings 118 may be applied to LED chips 116 to convert “blue” LED light to “white light.” One disadvantage of such photo down-conversion techniques is that they are static designs that cannot be adjusted in “real-time.” In other words, LED light bulbs using phosphor coatings can emit light only in the pre-designed color, and cannot be customized in real-time to alter the bulb's color output.
Light bulb 100 may further include an optic 120 to diffuse the light emitted from LED chips 116. Typical optics, however, are static components that offer little, or no, real-time modification or customization of the bulb's light output.
In practice, the assembly of light bulb 100 is a labor-intensive and costly process. First, the electrical components 112 are mounted and soldered onto PCB 110. Then, PCB 110 is inserted within cavity 106 of housing 104. Electrical leads 108 are coupled between base 102 and PCB 110. A potting compound is then inserted within cavity 106 to stabilize and set PCB 110 within housing 104. Heat sink 114 is then coupled to housing 104. LED chips 116 and optic 120 are then mounted on heat sink 114.
What is needed is an LED lighting system with fewer components, which is suitable for more automated and practical manufacturing methods. Additionally, what is needed is an LED lighting system that can be adjusted to suit varying lighting needs.